The dioxin found at the Centredale site is 2,3,7,8 TCDD, the most toxic of the dioxins and a known human carcinogen. For specific information on 2,3,7,8 TCDD see this PDF document on the Environmental Health Perspectives web site. Environmental Health Perspectives is the peer-reviewed journal of the National Institute of Environmental Health Sciences, which is part of the National Institutes of Health. For an easier to understand overview of 2,3,7,8 TCDD see this web page on the Eco-USA web site.

Pending further notice, the EPA will go ahead with its preferred plan for restoring dioxin-contaminated soils and sediments along the Woonasquatucket River in North Providence.

This is referred to as a Non-Time Critical Removal Action and the cleanup proposal involves three phases:

Excavation of contaminated residential soils and floodplain sediments at specific locations around Allendale and Lymansville Ponds

Restoration of the decaying Allendale Dam

Transportation of soils and sediments to off-site treatment and disposal facility

Economic breakdown of the cleanup:

On-site consolidation

$1.8 million

Off-site disposal

$2.3 million

Treatment

$2.6 million

Total costs:

$6.7 million

The public comment period ended December 3, 2000 and the EPA is in the process of evaluating comments and preparing an Action Memorandum.

The latest phase of the Remedial Investigation is the "Source Area Investigation" during which the EPA will focus on deeper soils and groundwater flow to determine if contaminants are traveling to the river from adjacent sediments.

The drilling of wells along both sides of the Woonasquatucket will occur in the next few months.

Enforcement action against potentially responsible parties (PRP's) continues with the release of five General Notice of Potential Liability letters. PRP's include chemical manufacturing and drum recycling companies that were located on the site over 30 years ago and may have released dioxins into the atmosphere and water supply.